//无端滚动的步骤
//1.定时器设置10ms
//2.获取所有的li的margin-left,margin-left--
//3.判断margin-left<2031px 就重置为0，否则就等于margin-left+"px"
//4.注意：需要使用parseint获取行内样式的数据
setInterval(function(){
let ulObj=document.querySelector(".hot ul")
let marginLeft=parseInt(ulObj.style.marginLeft)
marginLeft--
if(marginLeft<=-2032)
{
    ulObj.style.marginLeft="0px"
}else{
    ulObj.style.marginLeft=marginLeft+"px"
}}
,10)